Urinary System

Question 1

kidney functions

Answer 1

produce urine
eliminate nitrogenous waste
maintains electrolytes and water balance
release renin and erythropoietin

Question 2

location of the kidneys

Answer 2

posterior abdominal wall
behind peritoneum
each side of vertebral column at T12 - L3
epigastric, hypochondriac, lumbar, umbilical regions

Question 3

why is the right kidney slightly lower than the left

Answer 3

the liver is above the right kidney

Question 4

external features of kidneys

Answer 4

two poles, surfaces and borders
hilum - renal vein, artery, pelvis

Question 5

coverings of kidneys

Answer 5

from within outwards

fibrous capsule (true capsule)
perirenal (perinephric) fat
renal fascia (false capsule)
pararenal (paranephric) fat

Question 6

role of perirenal and pararenal fat

Answer 6

perirenal fat supports the kidney positionally
pararenal fat cushions and prevents the kidney hitting T11-12

Question 7

relations of the right kidney

Answer 7

liver, duodenum, colon, jejunum
only T12

Question 8

relations of left of kidney

Answer 8

stomach, pancreas, jejunum, colon, spleen
T11 and T12

Question 9

macroscopic structure of outer cortex

Answer 9

located below renal capsule and extends between the renal pyramids as renal columns which divide lobes

Question 10

macroscopic structure of inner medulla

Answer 10

5 - 11 dark renal pyramids with inner apex and outer base
form projections which invaginate the minor calyces

Question 11

renal sinus

Answer 11

cavity of considerable size within the kidney
opens at the medial border of the kidney as hilus
contains renal pelvis, calyces, vessels, nerves and fat

Question 12

microscopic structure

Answer 12

nephron is functional unit: glomerulus and tubule system

Question 13

functions of nephrons

Answer 13

filtration, selective reabsorption, secretion

Question 14

cortical vs juxta-medullary nephrons

Answer 14

cortical nephron: sodium resorption
more superficial with loops of Henle confined to cortex

juxta-medullary nephrons: water resorption
nephrons start more near the cortex-medulla junction with longer loops that extend into medulla

Question 15

renal corpuscle

Answer 15

mainly located in cortical arches
consists of capillaries and Bowman’s capsule
vascular pole

Question 16

proximal convoluted tubule

Answer 16

low columnar to cuboidal epithelium
luminal surface has microvilli brush border
main function: active reabsorption
glucose, amino acids, Na, Cl, HCO3, water

Question 17

loop of Henle

Answer 17

thin descending limb and thick ascending limb
function: reabsorbs water, Na, Cl

Question 18

distal convoluted tubule

Answer 18

begins from the vascular pole of the nephron
lined by cuboidal epithelium but no brush border
function: reabsorbs Na, Cl, water

Question 19

major blood supply of kidneys

Answer 19

arterial supply: renal artery branching from abdominal aorta

venous drainage: renal vein into IVC

Question 20

renal circulation

Answer 20

renal arteries divides into anterior and posterior on either side of renal pelvis
branches into segmental then lobar arteries
become interlobar arteries between medullary pyramids then arcuate arteries
then interlobular arteries which form glomeruli
drain via same but opposite

Question 21

juxtaglomerular apparatus
what is it made of

Answer 21

involved in regulation of blood pressure

made up of:
JG cells
macula densa
Lacis / Polkissen cells

Question 22

JG cells

Answer 22

modified smooth muscle cells
in tunica media of afferent arteriole at DCT
sensitive to blood pressure
responsible for RAAS

Question 23

macula densa

Answer 23

specialised regions in the wall of the DCT that contacts JG cells
columnar cells instead of cuboidal cells in the DCT
sensitive to conc of Na in DCT fluid

Question 24

Lacis / Polkissen cells

Answer 24

extraglomerular mesangial cells
at the vascular pole in close relationship with macula densa

Question 25

what causes activation of RAAS RAAS pathway

Answer 25

decreased BP or Na Renin converts angiotensinogen to angiotensin I ACE converts Ag I to Ag II Ag II causes vasoconstriction and release of aldosterone which increase NaCl absorption

Question 26

why is 8 mL of dye is inserted for urography

Answer 26

any more would distort the anatomy and less would be inaccurate

Question 27

congenital polycystic kidney disease

Answer 27

occurs because the DCT and CD have different embryonic origins if they do not fuse correctly, urine does not drain properly and cysts form

Question 28

horseshoe kidney

Answer 28

fusion of the inferior poles of the kidneys causes increased risk of stones and UTIs and impaired functions

Question 29

renal transplants

Answer 29

needed when there is chronic failure surgery via the right iliac fossa for ease due to vessels

Question 30

ureter

Answer 30

narrow, thick walled, expansile, muscular tube 25 cm 3.5 mm abdominal and pelvic are above and below the pelvic bone

Question 31

site of anatomical constrictions of the ureter

Answer 31

Pelviureteric junction pelvic brim where it crosses the common iliac artery utero-vesical junction (entry to bladder)

Question 32

blood supply of the ureter

Answer 32

arterial supply form the arteries related to it divide superiorly and inferiorly abdominal ureter supplied by arteries medial to it pelvic ureter supplied from arteries lateral to it

Question 33

where is the urinary bladder

Answer 33

situated in the anterior of the lesser pelvis immediately behind pubic symphysis

Question 34

external features of urinary bladder

Answer 34

apex at anterior and base at posterior two ureters enter at either side of the base superior surface and inferior neck in males prostate sits at the neck

Question 35

relations of the urinary bladder

Answer 35

anterior is pubic bone (symphysis) posterior in males is rectum, vas deferens and seminal vesicle posterior in females is vagina and uterus

Question 36

interior of the urinary bladder

Answer 36

rugae when empty but disappear as it stretches trigone of the bladder on the interior posterior surface which has no rugae because submucosa and muscular layer are fused two inputs from ureters one output to urethra

Question 37

urethra

Answer 37

longer in males than females females get UTIs more often but harder to treat in males membranous part is more internal and spongy part is in the penis

Question 38

sphincters of the urethra

Answer 38

internal sphincter is at the base of the bladder and involuntary external sphincter is at the base of the penis or before orifice and voluntary internal relaxes during urination but closes during ejaculation

Question 39

histology of the kidney

Answer 39

outer renal capsule round structures: Bowman's capsule fuzzy lumen: PCT clear lumen: DCT long structures: CDs and some LoH inner medulla is more condensed

Question 40

histology of ureter

Answer 40

upper ureter has two layers of muscle: outer circular and inner longitudinal lower has three: outer longitudinal, middle circular, inner longitudinal

Question 41

histology of the bladder

Answer 41

dome shaped cells below is muscle which is not distinctly arranged